X-ray diffraction
1.99Å resolution

Crystal structure of SARS coronavirus main protease complexed with Cm-FF-H (soaking)


Function and Biology Details

Reactions catalysed:
TSAVLQ-|-SGFRK-NH(2) and SGVTFQ-|-GKFKK the two peptides corresponding to the two self-cleavage sites of the SARS 3C-like proteinase are the two most reactive peptide substrates. The enzyme exhibits a strong preference for substrates containing Gln at P1 position and Leu at P2 position.
Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
Biochemical function:
  • not assigned
Biological process:
  • not assigned
Cellular component:
  • not assigned

Structure analysis Details

Assembly composition:
homo dimer (preferred)
Entry contents:
1 distinct polypeptide molecule
3C-like proteinase nsp5 Chain: A
Molecule details ›
Chain: A
Length: 306 amino acids
Theoretical weight: 33.88 KDa
Source organism: Severe acute respiratory syndrome-related coronavirus
Expression system: Escherichia coli
  • Canonical: P0C6U8 (Residues: 3241-3546; Coverage: 7%)
Gene name: 1a
Sequence domains: Coronavirus endopeptidase C30
Structure domains:

Ligands and Environments

1 bound ligand:
No modified residues

Experiments and Validation Details

Entry percentile scores
X-ray source: BESSY BEAMLINE 14.2
Spacegroup: C2
Unit cell:
a: 107.75Å b: 82.88Å c: 53.5Å
α: 90° β: 104.63° γ: 90°
R R work R free
0.22 0.217 0.27
Expression system: Escherichia coli